“Also if the waiter/Waitress doesn’t do a good job & you feel they don’t deserve a tip or less of a tip you are mechuyav to tell the Waiter/Waitress that you are not tipping them because of their bad service this way they know why you didn’t tip them & would avoid the chillul Hashem.”
That does nothing to reduce the alleged chillul Hashem. The waiter will hate you, or Jews, all the same if not more if you tell him to his face that he provided shoddy service so you’re not tipping him, then if you simply walked out without a tip or a comment.
Furthermore, your idea of telling him why you’re not tipping does nothing to alleviate many of the above reasons given in this thread as to who tipping is allegedly mandatory.